~ Scientifically Based Lake Restoration, Management & Protection

Author Archives: dickosgood2

Lake County IL – Another example that whatever we have been doing (or perhaps, not doing) is not leading to lake improvement. This story provides examples of attempts to mitigate pollution, but no real improvements.

To improve eutrophic or phosphorus-impaired lakes requires substantial, sustained reductions in incoming phosphorus as well as immobilizing internal phosphorus. Almost always, these involve interventions rather than tweaks.

In the commentary I explored options to achieve water quality goals referring to “end-of-pipe” solutions. I have received a number of comments and questions about this. In some cases, it was assumed I was referring to treatment on every field or property. To clarify, I was referring to treatment of non point source runoff as collected naturally (by streams) or artificially (ditches, pipes) at points well downstream from the original sources and near discharge points to receiving waters. Some also misunderstood “pipe” to refer to a point source. It actually refers to the end of some collection system receiving runoff (or non point source) pollution.

It was also suggest to let the buffer program work. I am still looking for evidence (based on objective assessments) that buffers will remove nutrients sufficiently to make a substantial difference in MN’s impaired waters.

Harry Gibbons and Dick Osgood, Lake Advocates founders, are leading a workshop titled, “Lake & Pond Phosphorus Inactivation & Interception.” This is the 14th year we have presented this workshop.

Workshop Description:

Phosphorus management through mitigating excess phosphorus loading to lakes from its watershed may be difficult, expensive and require many years before lake water quality is observed. Inactivation of phosphorus has been one of the most effective lake management tools and may be used to safely, quickly and efficiently eliminate water quality problems. The most effective phosphorus inactivation tool to date is aluminum sulfate (alum), although other precipitants are available and will be discussed. Alum’s use will be presented in the form of planning, design, application, and monitoring. Case studies will be discussed from a lessons learned and potential future use perspective. In addition to discussing partial and whole lake alum applications, alum use to remove phosphorus from the water column, to inactivate sediment phosphorus or intercept phosphorus in stormwater runoff and alum use in ponds; other inactivation and flocculant alternatives approaches will also be presented and discussed. Participants will learn about alum technologies and strategies through published literature overviews, third-party assessments, real-world data, case histories and participant interaction. Topics include internal and external phosphorus sources, alum precipitation chemistry (and other flocculant chemistry), application technologies and strategies, dose determination, phosphorus interception, effectiveness, longevity of phosphorus inactivation, and project examples. Techniques for evaluating the timing and magnitude internal and external phosphorus inputs will be reviewed in the context of designing alum application strategies. Differences between thermally stratified versus unstratified (polymictic) lakes will be discussed relative to application strategy. Regulations and permitting will be also be outlined and discussed. Participants will be encouraged to share their experiences during the workshop. Workshop includes a workshop manual with worksheets and a detailed bibliography.

The day-long workshop is help in association with the North American Lake Management Societies’ annual symposium on Tuesday, November 1st in Banff, Alberta.